Fossil Patterns and Common Ancestry is a Grade 7 Science worksheet focused on Biological Evolution: Unity and Diversity. The resource examines how fossil records and sedimentary rock layers reveal patterns in life over geologic time, with specific attention to index fossils, fossil assemblages, transitional fossils, diversification, radiation events, and mass extinctions.

Core Fossil Evidence

Students work with the principle that, in an undisturbed sequence, lower sedimentary rock layers are generally older than layers above them. They explore how index fossils help scientists compare rock-layer ages and how fossil assemblages can help correlate layers from different locations.

The lesson also introduces anatomical transitions through examples named in the resource. Students examine how Archaeopteryx has both dinosaur-like and bird-like features and how Tiktaalik has features associated with fish and four-limbed vertebrates. They also consider how diversification and mass extinction appear as patterns in the fossil record and what those patterns can reveal about biodiversity and common ancestry.

Student Practice

• Multiple-choice questions covering rock-layer age, index fossils, fossil assemblages, transitional fossils, Archaeopteryx, Tiktaalik, radiation events, mass extinctions, and common ancestry
• True-or-false questions that reinforce key statements about fossil evidence and biodiversity
• Short-answer questions requiring students to explain fossil-age patterns, anatomical transitions, and changes in biodiversity
• A labeled diagram activity for interpreting fossil and rock-layer patterns
• A categorization activity focused on evidence of ancestry and rock-layer dating
• Student notes for reviewing important concepts and vocabulary

Teacher Support

The Answer Key PDF includes a Teacher Guide with learning objectives, teaching tips, discussion questions, and common mistakes. These materials provide practical support for introducing fossil evidence, guiding discussion, reviewing student reasoning, and addressing common misconceptions.

Classroom Use

Use this fossil record worksheet for classroom instruction, independent practice, review, or assessment within a Grade 7 Science unit on biological evolution. The combination of informational reading, selected-response practice, written explanation, visual interpretation, categorization, and notes gives students multiple opportunities to apply the same core ideas about fossil evidence and common ancestry.

The resource is identified with the NGSS framework and keeps the focus on observable fossil patterns, relative relationships among rock layers, anatomical transitions, diversification, and mass extinction.